Someone else had this issue too, they weren't able to fix it but they were able to play using a controller. I understand this isn't ideal at all.
It is an engine bug that we have no control over unfortunately, and has been in Valve's code since Counter Strike 1.6 at least. You can search for "spinning bug" in counter-strike and find the issue goes back as far as 1.6 and Half-Life.
We've been looking for the solution, and found there would normally be ways to fix/prevent it using console commands or launch parameters but Valve withholds some features and commands from Source SDK Base that could help (we have no clue why) and also broke launch parameters about a month ago.